Hi,
I used to work with a SSD1306 for a project, but now I want to upgrade the display and use a ST7735.
If I understand correctly, SSD1306 works with I2C and need SDA/SCL on pins 20(SDA) and 21(SCL) th rest was handled by the library.
Now with ST7735, it's SPI that is used. I have a cheap oled display that is labelled with GND, VCC, SCL, SDA, RES, DC, CS, BLK(https://www.amazon.fr/DollaTek-Pouces-80x160-Color-Arduino/dp/B07QCSH5P4)
I wired like this:
display <-> MCU
GND <-> GND
VCC <-> VCC
SCL <-> D21 (SCL)
SDA <-> D20(SDA)
RES <-> Nothing
DC <-> D22
CS <-> D23
BLK <-> D24
I try many thing because it's not well documented.
Like use SDA/SCL next to D13 labelled pin on mega, SDA/SCL pins 20 & 21, I see somewhere D51 and D52 where SCL/SDA pins...
Nothing prints one the screen, the backlight doesn't lit too.
And the code I use:
#include <Adafruit_GFX.h> // Core graphics library
#include <Adafruit_ST7735.h> // Hardware-specific library for ST7735
#include <Adafruit_ST7789.h> // Hardware-specific library for ST7789
#include <Adafruit_GrayOLED.h>
#include <SPI.h>
/*
Mapping SPI for Arduino Mega
Chinese Display - MCU
GND <-> GND
VCC <-> VCC
SCL <-> D21 SCL
SDA <-> D20 SDA
RES <->
DC <->
CS <->
BLK <->
RES = Reset
*/
#define TFT_DC 22
#define TFT_CS 23
#define TFT_RST -1 // Or set to -1 and connect to Arduino RESET pin
Adafruit_ST7735 tft = Adafruit_ST7735(TFT_CS, TFT_DC, -1);
float p = 3.1415926;
void testlines(uint16_t color)
{
tft.fillScreen(ST77XX_BLACK);
for (int16_t x = 0; x < tft.width(); x += 6)
{
tft.drawLine(0, 0, x, tft.height() - 1, color);
delay(0);
}
for (int16_t y = 0; y < tft.height(); y += 6)
{
tft.drawLine(0, 0, tft.width() - 1, y, color);
delay(0);
}
tft.fillScreen(ST77XX_BLACK);
for (int16_t x = 0; x < tft.width(); x += 6)
{
tft.drawLine(tft.width() - 1, 0, x, tft.height() - 1, color);
delay(0);
}
for (int16_t y = 0; y < tft.height(); y += 6)
{
tft.drawLine(tft.width() - 1, 0, 0, y, color);
delay(0);
}
tft.fillScreen(ST77XX_BLACK);
for (int16_t x = 0; x < tft.width(); x += 6)
{
tft.drawLine(0, tft.height() - 1, x, 0, color);
delay(0);
}
for (int16_t y = 0; y < tft.height(); y += 6)
{
tft.drawLine(0, tft.height() - 1, tft.width() - 1, y, color);
delay(0);
}
tft.fillScreen(ST77XX_BLACK);
for (int16_t x = 0; x < tft.width(); x += 6)
{
tft.drawLine(tft.width() - 1, tft.height() - 1, x, 0, color);
delay(0);
}
for (int16_t y = 0; y < tft.height(); y += 6)
{
tft.drawLine(tft.width() - 1, tft.height() - 1, 0, y, color);
delay(0);
}
}
void testdrawtext(char *text, uint16_t color)
{
tft.setCursor(0, 0);
tft.setTextColor(color);
tft.setTextWrap(true);
tft.print(text);
}
void testfastlines(uint16_t color1, uint16_t color2)
{
tft.fillScreen(ST77XX_BLACK);
for (int16_t y = 0; y < tft.height(); y += 5)
{
tft.drawFastHLine(0, y, tft.width(), color1);
}
for (int16_t x = 0; x < tft.width(); x += 5)
{
tft.drawFastVLine(x, 0, tft.height(), color2);
}
}
void testdrawrects(uint16_t color)
{
tft.fillScreen(ST77XX_BLACK);
for (int16_t x = 0; x < tft.width(); x += 6)
{
tft.drawRect(tft.width() / 2 - x / 2, tft.height() / 2 - x / 2, x, x, color);
}
}
void testfillrects(uint16_t color1, uint16_t color2)
{
tft.fillScreen(ST77XX_BLACK);
for (int16_t x = tft.width() - 1; x > 6; x -= 6)
{
tft.fillRect(tft.width() / 2 - x / 2, tft.height() / 2 - x / 2, x, x, color1);
tft.drawRect(tft.width() / 2 - x / 2, tft.height() / 2 - x / 2, x, x, color2);
}
}
void testfillcircles(uint8_t radius, uint16_t color)
{
for (int16_t x = radius; x < tft.width(); x += radius * 2)
{
for (int16_t y = radius; y < tft.height(); y += radius * 2)
{
tft.fillCircle(x, y, radius, color);
}
}
}
void testdrawcircles(uint8_t radius, uint16_t color)
{
for (int16_t x = 0; x < tft.width() + radius; x += radius * 2)
{
for (int16_t y = 0; y < tft.height() + radius; y += radius * 2)
{
tft.drawCircle(x, y, radius, color);
}
}
}
void testtriangles()
{
tft.fillScreen(ST77XX_BLACK);
uint16_t color = 0xF800;
int t;
int w = tft.width() / 2;
int x = tft.height() - 1;
int y = 0;
int z = tft.width();
for (t = 0; t <= 15; t++)
{
tft.drawTriangle(w, y, y, x, z, x, color);
x -= 4;
y += 4;
z -= 4;
color += 100;
}
}
void testroundrects()
{
tft.fillScreen(ST77XX_BLACK);
uint16_t color = 100;
int i;
int t;
for (t = 0; t <= 4; t += 1)
{
int x = 0;
int y = 0;
int w = tft.width() - 2;
int h = tft.height() - 2;
for (i = 0; i <= 16; i += 1)
{
tft.drawRoundRect(x, y, w, h, 5, color);
x += 2;
y += 3;
w -= 4;
h -= 6;
color += 1100;
}
color += 100;
}
}
void tftPrintTest()
{
tft.setTextWrap(false);
tft.fillScreen(ST77XX_BLACK);
tft.setCursor(0, 30);
tft.setTextColor(ST77XX_RED);
tft.setTextSize(1);
tft.println("Hello World!");
tft.setTextColor(ST77XX_YELLOW);
tft.setTextSize(2);
tft.println("Hello World!");
tft.setTextColor(ST77XX_GREEN);
tft.setTextSize(3);
tft.println("Hello World!");
tft.setTextColor(ST77XX_BLUE);
tft.setTextSize(4);
tft.print(1234.567);
delay(1500);
tft.setCursor(0, 0);
tft.fillScreen(ST77XX_BLACK);
tft.setTextColor(ST77XX_WHITE);
tft.setTextSize(0);
tft.println("Hello World!");
tft.setTextSize(1);
tft.setTextColor(ST77XX_GREEN);
tft.print(p, 6);
tft.println(" Want pi?");
tft.println(" ");
tft.print(8675309, HEX); // print 8,675,309 out in HEX!
tft.println(" Print HEX!");
tft.println(" ");
tft.setTextColor(ST77XX_WHITE);
tft.println("Sketch has been");
tft.println("running for: ");
tft.setTextColor(ST77XX_MAGENTA);
tft.print(millis() / 1000);
tft.setTextColor(ST77XX_WHITE);
tft.print(" seconds.");
}
void mediabuttons()
{
// play
tft.fillScreen(ST77XX_BLACK);
tft.fillRoundRect(25, 10, 78, 60, 8, ST77XX_WHITE);
tft.fillTriangle(42, 20, 42, 60, 90, 40, ST77XX_RED);
delay(500);
// pause
tft.fillRoundRect(25, 90, 78, 60, 8, ST77XX_WHITE);
tft.fillRoundRect(39, 98, 20, 45, 5, ST77XX_GREEN);
tft.fillRoundRect(69, 98, 20, 45, 5, ST77XX_GREEN);
delay(500);
// play color
tft.fillTriangle(42, 20, 42, 60, 90, 40, ST77XX_BLUE);
delay(50);
// pause color
tft.fillRoundRect(39, 98, 20, 45, 5, ST77XX_RED);
tft.fillRoundRect(69, 98, 20, 45, 5, ST77XX_RED);
// play color
tft.fillTriangle(42, 20, 42, 60, 90, 40, ST77XX_GREEN);
}
void setup(void)
{
Serial.begin(9600);
Serial.print(F("Hello! ST77xx TFT Test"));
tft.initR(INITR_MINI160x80); // Init ST7735S mini display
Serial.println(F("Initialized"));
uint16_t time = millis();
tft.fillScreen(ST77XX_BLACK);
time = millis() - time;
Serial.println(time, DEC);
delay(500);
// large block of text
tft.fillScreen(ST77XX_BLACK);
testdrawtext("Lorem ipsum dolor sit amet, consectetur adipiscing elit. Curabitur adipiscing ante sed nibh tincidunt feugiat. Maecenas enim massa, fringilla sed malesuada et, malesuada sit amet turpis. Sed porttitor neque ut ante pretium vitae malesuada nunc bibendum. Nullam aliquet ultrices massa eu hendrerit. Ut sed nisi lorem. In vestibulum purus a tortor imperdiet posuere. ", ST77XX_WHITE);
delay(1000);
// tft print function!
tftPrintTest();
delay(4000);
// a single pixel
tft.drawPixel(tft.width() / 2, tft.height() / 2, ST77XX_GREEN);
delay(500);
// line draw test
testlines(ST77XX_YELLOW);
delay(500);
// optimized lines
testfastlines(ST77XX_RED, ST77XX_BLUE);
delay(500);
testdrawrects(ST77XX_GREEN);
delay(500);
testfillrects(ST77XX_YELLOW, ST77XX_MAGENTA);
delay(500);
tft.fillScreen(ST77XX_BLACK);
testfillcircles(10, ST77XX_BLUE);
testdrawcircles(10, ST77XX_WHITE);
delay(500);
testroundrects();
delay(500);
testtriangles();
delay(500);
mediabuttons();
delay(500);
Serial.println("done");
delay(1000);
}
void loop()
{
tft.invertDisplay(true);
delay(500);
tft.invertDisplay(false);
delay(500);
}
Thanks
